Fertility awareness and charting is part of 'Natural Family Planning' (NFP) and uses a woman's natural fertility signs to identify when she may or may not be fertile. You can learn quickly how to identify your fertile and infertile phases by charting these three primary fertility signs:

  1. Basal body temperature (BBT)
  2. Cervical mucus (CM)
  3. Cervical position and consistency

Many couples use this fertility awareness to optimize chances for conceiving a child or preventing a pregnancy ["Natural Family Planning" (NFP)].

Fertility awareness-based methods attempt to determine the days in a woman’s menstrual cycle when she is fertile, that is when an ovum has been released from the ovary and is capable of being fertilized. Fertility awareness-based methods either estimate when ovulation is most likely to occur or indicates when ovulation has already taken place. These methods are most useful when a woman has regular and predictable menstrual cycles.

On days when fertility is greatest, a couple can use an alternative barrier method of birth control, such as condoms or a diaphragm; enjoy ways of sexual pleasuring other than genital intercourse, or abstain from sexual contact completely.

Using Fertility Awareness-Based Methods Effectively
Fertility awareness-based methods offer the advantages of being safe and inexpensive. For some couples, religious convictions make fertility awareness-based methods the only acceptable method of birth control. Failures can occur when using these methods because people do not keep careful records, women may have irregular or minimally symptomatic cycles, couples may find the intervals of abstinence during the fertile days too long, or they find that having to plan sex a hindrance to spontaneous lovemaking. Fertility awareness-based methods require that both partners have a strong commitment to using the techniques correctly and consistently.

The Standard Days Method (SDM) and the Calendar Rhythm Method, involve counting the days in the menstrual cycle and require that the woman knows which day of her menstrual cycle she is on. For the SDM she is considered fertile between days 8 through 19 counting day 1 as the first day of menstruation. Women can use SDM if they have regular cycles never shorter than 26 days or longer than 32 days. Another method is the Calendar Rhythm Method.

There are also home test kits available for ovulation prediction and detection that can be used to detect the fertile window of the menstrual cycle for contraceptive purposes.


  • Greater involvement of partner to avoid pregnancy
  • No prescription needed
  • Increased communication between the couple
  • Increased awareness of how to become pregnant if conception is desired


  • High failure rate if not used consistently and correctly
  • Fewer "safe" days to have intercourse each month'
  • Training is essential
  • Breastfeeding, illness and other factors can obscure fertility signs
  • No protection from STIs
  • If periods are not regular, may not be as effective

Failure rate: Typical use: 25%; Perfect use: 3-5%